Many solutions have been proposed to provide continued vehicle mobility after loss of inflation pressure in a pneumatic tire. One class of solutions involves fixing a rigid or semi-rigid insert to the wheel rim and inside the tire. Upon loss of inflation pressure, the vehicle is supported by load transmission from the portion of the insert contacting the inside of the tire directly through the insert structure to the wheel rim. However, a solution having a structurally supported runflat insert that delivers pneumatic tire-like performance would be a welcome performance improvement.